comparison rust/hg-core/src/dirstate/status.rs @ 47347:73ddcedeaadf

dirstate-tree: Change status() results to not borrow DirstateMap

The `status` function takes a `&'tree mut DirstateMap<'on_disk>` parameter.
`'on_disk` borrows a read-only byte buffer with the contents of the
`.hg/dirstate` file. `DirstateMap` internally uses represents file paths as
`std::borrow::Cow<'on_disk, HgPath>`, which borrows the byte buffer when
possible and allocates an owned string if not, such as for files added to the
dirstate after it was loaded from disk.

Previously the return type of of `status` has a `'tree` lifetime, meaning it
could borrow all paths from the `DirstateMap`. With this changeset, that
lifetime is changed to `'on_disk` meaning that only paths from the byte buffer
can be borrowed, and paths allocated by `DirstateMap` must be copied.

Usually most paths are in the byte buffer, and most paths are not part of the
return value of `status`, so the number of extra copies should be small.

This change will enable `status` to mutate the `DirstateMap` after it has
finished constructing its return value. Previously such mutation would be
prevented by possible on-going borrows.

Differential Revision: https://phab.mercurial-scm.org/D10824

47346:5e12b6bfdd3e

    /// alone. The file contents need to be read and compared with that in
    /// the parent.
    pub unsure: Vec<HgPathCow<'a>>,

    /// Only filled if `collect_traversed_dirs` is `true`
    pub traversed: Vec<HgPathBuf>,
}

#[derive(Debug, derive_more::From)]
pub enum StatusError {
    /// Generic IO error

}

#[timed]
pub fn build_response<'a>(
    results: impl IntoIterator<Item = DispatchedPath<'a>>,
    traversed: Vec<HgPathBuf>,
) -> DirstateStatus<'a> {
    let mut unsure = vec![];
    let mut modified = vec![];
    let mut added = vec![];
    let mut removed = vec![];

47347:73ddcedeaadf

    /// alone. The file contents need to be read and compared with that in
    /// the parent.
    pub unsure: Vec<HgPathCow<'a>>,

    /// Only filled if `collect_traversed_dirs` is `true`
    pub traversed: Vec<HgPathCow<'a>>,
}

#[derive(Debug, derive_more::From)]
pub enum StatusError {
    /// Generic IO error

}

#[timed]
pub fn build_response<'a>(
    results: impl IntoIterator<Item = DispatchedPath<'a>>,
    traversed: Vec<HgPathCow<'a>>,
) -> DirstateStatus<'a> {
    let mut unsure = vec![];
    let mut modified = vec![];
    let mut added = vec![];
    let mut removed = vec![];